A RUTHLESS KILLER is part of an international conspiracy in a new episode of the mystery series “Castle” at 10 p.m. on ABC. With Nathan Fillion, left, Stana Katic and Jennifer Beals.

SERIES

The Voice: Blind auditions for this unscripted singing competition continue (8 p.m. NBC).House: Chase (Jesse Spencer) forges a bond with the team’s latest patient (Julie Mond), a cloistered nun who is about to take her final vows in this new episode (8 p.m. Fox).The Real Housewives of Beverly Hills: The troubled unscripted series reunion episodes continue at 8 and 9 8 p.m. on Bravo.Undercover Boss: Abroad: The American series goes international premiering with David Clarke on an undercover mission to examine the inner workings of Best Western (9 p.m. TLC).Smash: Ivy and Karen (Megan Hilty and Katharine McPhee) work to please the director (Jack Davenport) as they pursue their dream role in a new episode of the musical series (10 p.m. NBC).